how to explain the sample size discrepancy in UCSC Xena

Question

[nuorain]

For HNSC, the sample size for Phenotype is 604, the sample size for survival is 603. The sample size for gene expression RNAseq is 566. Why aren't they the same number? Thanks.

Answer 1

[i.sudbery]

Because there wasn't RNA-seq analysis performed for every sample in TCGA?

[nuorain]

Thank you very much.